Lifetime mattress warranties: what they actually cover

Online mattress brands compete on warranty length: 10 years, 25 years, "lifetime", "forever". The length matters much less than the fine print. Here is what to read before you rely on one.

1. The sag depth that counts as a defect

Warranties don't cover a mattress for feeling softer. They cover a body impression deeper than a set measurement, measured with no one on the bed. Across brands, that threshold usually falls between 0.75 and 1.5 inches.

Two examples from Tom's Guide's warranty coverage:

• Nectar requires a visible indentation of at least 1.5 inches.
• Layla covers sagging of one inch or more.

A smaller number is better for you: a mattress can feel worn out well before it sags 1.5 inches.

How to measure: stretch a string or lay a straight edge across the mattress over the dip, then measure from it down to the deepest point. Take photos with the ruler in view.

2. "Lifetime" usually changes after year 10

Many lifetime warranties have two phases. According to Tom's Guide:

• Nectar replaces a defective mattress free during the first 10 years. After that, repairs, re-covers, or replacements carry a $50 transport fee each way, which can be waived if Nectar confirms a defect.
• DreamCloud works the same way: free replacement for defects in the first 10 years, then a $50 transport fee each way.

Other brands prorate later years, meaning you pay a growing share of the price. Always look for the words "prorated" or "non-prorated" and what changes after year 10.

3. What voids a warranty

These are the most common reasons claims get denied:

• Any stain. Several retailers report that almost every warranty is voided by any stain, even a small one. Brooklyn Bedding's policy, for example, excludes products that are stained, abused, damaged, burned, moisture saturated, cut, or torn. Use a waterproof protector from the first night.
• The wrong foundation. Warranties usually require a solid base or slats spaced closely together. An old box spring may not qualify.
• A removed law tag. Leave the tag on.
• Not the original buyer. Most warranties don't transfer if you buy the mattress used or move it to a new owner.
• No proof of purchase. Keep the receipt or order email.

4. How to file, and what to do if you're denied

1. Measure the dip and photograph it with a ruler, plus photos of your foundation and the law tag.
2. Contact the brand in writing with the order number, photos, and measurements.
3. If you're denied, appeal in writing and address the stated reason with evidence. A KENS 5 investigation showed a denial reversed after the owner sent photos showing the problem.
4. If that fails, contact your state or provincial consumer protection office.

Bottom line

Compare warranties on three things: the sag threshold, what changes after year 10, and the support requirements, not just the number of years. Then compare prices. Our tracker shows what every mattress really sells for, and how its price has moved, so a long warranty doesn't come with an inflated price.